PARIS (AP) — A regional train hit a school bus on a crossing in southern France Thursday, killing four children and critically injuring 11 other people on the bus, the French interior ministry said.

Photos from the scene tweeted by a local television station showed the train derailed and the bus shorn in half — with first responders gathered around.

French Prime Minister Edouard Philippe, who flew to the scene of the accident Thursday night, said that authorities still don’t know what led to the accident on the crossing in Millas, some 15 kilometers (9 miles) west of Perpignan, close to the border with Spain.

Philippe said that the “circumstances of this terrible drama are still undetermined.”

He confirmed that two inquiries are underway into the shocking accident that left four children dead, and injured 20 others — including 11 seriously.

France’s SNCF national rail authority said witnesses described the crossing gates as functioning properly. Regional President Carole Delga told broadcaster France-Info that “it appears that there was no mechanical problem at this crossing.”

The school bus was transporting children home from the Christian Bourquin school in the small village of Millas. It was carrying around 20 children aged between 11 and 15, the local authority said.

Psychological help is being offered in a local sports hall from Friday morning.

A school bus and a regional train collided killing four children and critically injuring several other people on the bus, the French interior ministry said. ()

(France Bleu via AP)

An SNCF official told The Associated Press that the train was carrying 25 people including passengers and crew and all are accounted for and being offered psychological care. The official added that that train normally travels at 80 kilometers per hour at that location.

The official said “several witnesses said the barrier was down” at the time of the crash. She said the people on the train were “totally shocked.”

Transport Minister Elisabeth Borne and Education Minister Jean-Michel Blanquer were at the scene Thursday evening along with 70 firefighters, 10 emergency ambulances and four helicopters.

Blanquer tweeted: “France is in mourning.”

French President Emmanuel Macron tweeted: “All my thoughts go to the victims of this terrible accident and their families. The government is fully mobilized to give them emergency help.”

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